Training.

"In less than 90 seconds, the brief video below will shatter countless excuses related to exercise and fitness. Within the clip, you will see a man work through a brief conditioning circuit. After a few rounds of the circuit, he’s able to achieve a quality, full body workout with minimal equipment. What’s even more impressive is that the man seen within was born in 1941.
In summary, here’s a man in his 70s achieving a quality workout with minimal equipment in minimal time. He doesn’t need any special equipment or routines to stay in better condition than the vast majority of adults who are half his age.
The take home message is simple. If you want to get in shape, get in shape. Consistency and discipline are far more important than any equipment or facility. Don’t be fooled by the fitness industry’s deception. There are no secrets to fat loss or fitness. You have everything that you’ll ever need to get in shape. You just need to use it."